Tire Bubble problems of the 2000 Chevrolet Astro

The contact owns a 2000 Chevrolet Astro van with delta esteem xle tires. Within a month after two tires were purchased by the same manufacture. He was traveling at 75 mph the vehicle started to severely shake. He pulled over to inspect the tires but was unable to find the failure. He then preceded to drive at 50 mph and took the vehicle straight to a dealer. The mechanic there inspected the vehicle and noticed severe thread separation and bubbles on the side of the front driver side tire. The tire was then replaced. A few months later he was traveling at 75mph when the vehicle started shaking. Before attempting to pull over to the side of the road the remaining delta tire that was located on the front passenger side blew out. He replaced the tire but he believes that the tires where defected and should be recalled. The failure mileage was 370,000. The current mileage is 380,000. -.